A dual modified heteropoly acid catalyst, a preparation method and application thereof

Abstract

The application discloses a kind of double modified heteropoly acid catalyst and its preparation method and application, belong to catalyst technical field.The double modified heteropoly acid catalyst of the application is composed of active component heteropoly acid, hydrophobic agent and silane double modified carrier;With the weight of double modified carrier, the loading of the heteropoly acid is 2-40wt%.The double modified heteropoly acid catalyst of the application improves the hydrophobicity of catalyst by the synergistic effect of hydrophobic agent and silane, which is beneficial to reduce the loss of active component;The catalyst has good dispersibility in reaction liquid, and high catalytic activity.The double modified heteropoly acid catalyst of the application is applied to the synthesis of dicumyl peroxide, and the reaction conditions are mild, the side reactions are few, the generation of byproduct AMS (alpha-methyl styrene) can be reduced, the conversion rate of CHP and the selectivity of DCP are improved.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a dual-modified heteropolyacid catalyst, its preparation method, and its application in the synthesis of dicumyl peroxide. Background Technology

[0002] Currently, the industrial production of dicumyl peroxide (DCP) typically uses dimethyl benzyl alcohol (DMBA) and cumyl hydroperoxide (CHP) as raw materials, employing perchloric acid as a catalyst, and carrying out a condensation reaction in a batch reactor to produce dicumyl peroxide and water. This method has the advantages of mature technology and low cost of perchloric acid catalyst, but it also has disadvantages such as severe equipment corrosion caused by perchloric acid, difficulty in separating perchloric acid from the product, numerous reaction byproducts, and potential environmental pollution.

[0003] Patent CN103145597B discloses a method for producing dicumyl peroxide, which uses different diluents to dilute strong protic acids to a low concentration, mainly to solve the problem of high byproduct α-MS in the prior art.

[0004] In patent CN104860861B, the acid catalyst is selected from at least three of hydrochloric acid, sulfuric acid, perchloric acid, phosphoric acid, and alkaline ionic liquid. This method has the advantages of high DCP selectivity and high product yield.

[0005] However, the above method uses liquid catalysts, which cannot overcome the disadvantages of liquid catalysts such as easy corrosion of equipment, difficulty in separation, and inability to be recycled.

[0006] Patent CN113845457B discloses a method using SO4 2- The method for preparing dicumyl peroxide using ZnCl2-HY solid acid has been proposed, but the catalyst has poor hydrophobicity, which easily leads to the loss of active components, and the selectivity and yield of the product DCP are low.

[0007] Heteropolyacids are a class of oxy-containing polyacids composed of polyatomic and heteroatomic atoms linked by oxygen atoms in a specific structure. Compared to perchloric acid, heteropolyacids have advantages such as strong acidity, safety, non-corrosiveness, and easy recovery. The main disadvantages of heteropolyacids are their relatively small specific surface area, a relatively small number of acidic active sites on their surface, and high solubility in polar media. In practical applications, heteropolyacids are usually loaded onto supports with high specific surface area to increase the specific surface area, and their surface is modified by silanization to improve their hydrophobicity. Summary of the Invention

[0008] Objective of this invention: To address the shortcomings of existing technologies, this invention provides a dual-modified heteropolyacid catalyst, its preparation method, and its application. This invention involves dual modification of the support using a hydrophobic agent and silane. When the resulting dual-modified heteropolyacid catalyst is used in the synthesis of dicumyl peroxide, the reaction conditions are mild, side reactions are few, and the generation of the byproduct AMS (α-methylstyrene) during the preparation of dicumyl peroxide is reduced, thereby improving the conversion rate and selectivity of the dicumyl peroxide synthesis reaction.

[0009] Technical solution: The objective of this invention is achieved through the following technical solution:

[0010] This invention provides a dual-modified heteropolyacid catalyst, which is composed of an active component heteropolyacid, a hydrophobic agent, and a silane-modified support; the loading of the heteropolyacid is 2-40 wt% based on the weight of the dual-modified support.

[0011] Preferably, the loading of the heteropoly acid is 10–30 wt%.

[0012] This invention modifies the support by using a hydrophobic agent and silane. The hydrophobic agent particles adsorb onto the support surface to change the surface roughness, while the silane bonds to the support surface to introduce hydrophobic groups. At the same time, the tightly packed network silane layer formed on the modified support surface firmly fixes the hydrophobic agent particles to the support surface. The hydrophobic agent and silane work synergistically to form a double hydrophobic layer structure, which improves the hydrophobicity of the catalyst.

[0013] In a preferred embodiment of the present invention, the active component, heteropolyacid, has the chemical formula H2. a X 3-a YM b Z 12-b O 40 X is one of Li, Na, K, and Cs; Y is one of P, Si, As, and Ge; M is one of Mo, W, and V; and Z is one of the Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, and La series metals; where a = 0 to 3 and b = 1 to 12.

[0014] More preferably, X is one of K and Cs; Y is one of P and As; M is one of Mo, W, and V; and Z is one of Cr, Co, Ni, Cu, and La metals.

[0015] More preferably, a = 1 to 2, b = 6 to 10.

[0016] Preferably, the hydrophobic agent comprises alkane C n H 2n+2 n = 15 to 40, one or more of stearic acid and its salts;

[0017] More preferably, the hydrophobic agent is selected from alkane C. n H 2n+2 (n=15~40), with alkane C being further preferred. n H 2n+2 (n=28~40), specifically taking wax as an example, its melting point is 50~120℃, preferably 90~110℃.

[0018] Preferably, the chemical formula of the silane is Y(CH2). n SiX3, n = 0 to 3, where X is chloro, methoxy, ethoxy, methoxyethoxy, or acetoxy, and Y is alkyl, aryl, vinyl, amino, epoxy, methacryloyloxy, mercapto, or urea; the silane is selected from one or more of the above-mentioned silanes.

[0019] More preferably, n = 1 to 3, X is methoxy, ethoxy, or methoxyethoxy; Y is amino.

[0020] More preferably, the silane is selected from at least one silane including aminosilane.

[0021] Preferably, the body of the carrier is selected from one or more of silicone, SBA-15, MCM-41, and ZSM-35.

[0022] Furthermore, the bulk material of the carrier is selected from silica gel; wherein the silica gel carrier has an average pore size of 10–40 nm and a specific surface area of ​​100–300 m². 2 / g.

[0023] Furthermore, the average pore size of the silica carrier is 15–30 nm; the specific surface area is 200–300 m². 2 / g.

[0024] The present invention also provides a method for preparing the dual-modified heteropolyacid catalyst, comprising the following steps:

[0025] (1) Dissolve the active component heteropoly acid in anhydrous ethanol and stir until homogeneous to obtain a heteropoly acid solution;

[0026] (2) The support modified by hydrophobic agent and silane was immersed in heteropoly acid solution at 10-60℃ for 5-24h, stirred, filtered and washed, and dried at 40-120℃ for 5-20h to obtain the dual-modified heteropoly acid catalyst.

[0027] The molar ratio of the silane to the heteropolyacid is 1 to 3:1.

[0028] Preferably, the immersion temperature is 20–50°C; the immersion time is 8–16 h; the drying temperature is 60–90°C; and the drying time is 6–15 h.

[0029] Preferably, in step (1), the active component heteropolyacid is prepared by the following method:

[0030] (a) Dissolve the compound containing the active component element in water and mix thoroughly; adjust the pH of the solution to 1-5 with dilute nitric acid and reflux at 30-120°C for 2-12 hours with stirring.

[0031] (b) Cool, extract, and evaporate the liquid obtained in step (a) to obtain heteropoly acid;

[0032] The compound containing the active component element is one or more of the following: oxides, hydroxides, nitrates, chlorides, acetates, or carbonates containing the active component.

[0033] Furthermore, the pH of the solution is adjusted to 1-4 with dilute nitric acid, and then stirred and refluxed at 50-100°C for 3-8 hours.

[0034] Preferably, in step (2), the dual-modified carrier is prepared by the following method:

[0035] (a) The pretreated carrier is dispersed in solvent 1 and stirred to obtain dispersion A at a stirring speed of 200-1000 rpm; the hydrophobic agent is dispersed in solvent 1 and stirred to obtain dispersion B at a stirring speed of 200-1000 rpm; the weight ratio of the hydrophobic agent to the carrier is 5-20:100.

[0036] (b) Add dispersion B to dispersion A and stir at 40-100°C for 2-8 hours at a stirring speed of 200-800 rpm. Dry the product at 50-90°C for 12-24 hours to obtain a hydrophobic agent modified carrier.

[0037] (c) The hydrophobic modified carrier obtained above is dispersed in solvent 2, and then silane is added. The mixture is refluxed at 30-90°C for 2-10 hours, filtered, washed, and dried to obtain the double-modified carrier.

[0038] Furthermore, the calcination temperature of the calcination pretreatment is 200–600℃, preferably 300–500℃; the calcination time is 2–12 h, preferably 3–8 h. The calcination pretreatment removes physicochemically adsorbed water from the carrier, thereby activating the carrier.

[0039] Further, solvent 1 is selected from one or more of methanol, ethanol, or isopropanol, preferably anhydrous ethanol; solvent 2 is selected from one or two of ethanol or methanol, preferably anhydrous ethanol. Solvent 1 and solvent 2 may be the same or different.

[0040] Further, in step (a), the stirring speed is 300-800 rpm; in step (b), the stirring speed is 300-600 rpm.

[0041] Further, in step (b), the stirring temperature is 70–100°C; the stirring time is 3–6 h; the drying temperature is 70–80°C; and the drying time is 12–18 h.

[0042] Furthermore, in step (c), the reflux temperature is 50–80°C; the reflux time is 4–8 hours.

[0043] A preferred embodiment of the present invention is a method for preparing the dual-modified heteropolyacid catalyst, comprising the following three parts: preparation of the active component heteropolyacid; preparation of the dual-modified support; and preparation of the dual-modified heteropolyacid catalyst.

[0044] The present invention also provides the application of the aforementioned dual-modified heteropolyacid catalyst in the synthesis of dicumyl peroxide.

[0045] The condensation reaction is carried out in a batch reactor or a continuous fixed bed using dimethylbenzyl alcohol and cumene hydroperoxide as raw materials and the dual-modified heteropolyacid catalyst of the present invention as a solid acid catalyst.

[0046] A preferred embodiment of the present invention uses dimethylbenzyl alcohol and cumene hydroperoxide as raw materials, with a molar ratio of dimethylbenzyl alcohol to cumene hydroperoxide of 0.9–1.2:1; the dual-modified heteropolyacid catalyst is added to cumene hydroperoxide at a weight ratio of 0.03%–0.3%:1; the reaction temperature is 30–50°C, the vacuum degree is -0.02–-0.08 MPa, and the reaction time is 2–8 h.

[0047] Further, the molar ratio of dimethylbenzyl alcohol to cumene hydroperoxide is 1.0 to 1.1:1; the dual-modified heteropolyacid catalyst is added to cumene hydroperoxide at a weight ratio of 0.05% to 0.20%:1.

[0048] Furthermore, the reaction is carried out in a batch reactor, the reaction temperature is 35–45°C, the vacuum degree is -0.02–-0.05 MPa, and the reaction time is 2–6 h.

[0049] The dual-modified heteropolyacid catalyst of the present invention first undergoes hydrophobic agent adsorption modification on the support. The hydrophobic agent particles attached to the support surface and the resulting rough surface microstructure together constitute the hydrophobic surface of the support. The hydrophobic agent-modified support is then modified with silane. The silanol groups on the support undergo a dehydroxylation and siloxane reaction, grafting organic hydrophobic groups onto the support surface, thereby improving hydrophobicity. At the same time, after silane modification, a tight network silane layer is formed on the support surface, which firmly locks the hydrophobic agent particles onto the support, thus forming a double-layer hydrophobic structure of the support.

[0050] Beneficial effects:

[0051] 1. The dual-modified heteropolyacid catalyst of the present invention improves the hydrophobicity of the catalyst through the synergistic effect of the hydrophobic agent and silane, which helps to reduce the loss of active components; the catalyst has good dispersibility in the reaction solution and high catalytic activity.

[0052] 2. Applying the dual-modified heteropolyacid catalyst of the present invention to the synthesis of dicumyl peroxide results in mild reaction conditions, fewer side reactions, reduced generation of byproduct AMS (α-methylstyrene), and improved CHP conversion and DCP selectivity.

[0053] 3. The dual-modified heteropolyacid catalyst of the present invention reduces corrosion to equipment, facilitates easy separation of catalyst and product, simplifies post-processing, allows for recycling, reduces emissions of waste, and enables continuous production of dicumyl peroxide. Detailed Implementation

[0054] The technical solution of the present invention will be described in detail below through specific embodiments, but the scope of protection of the present invention is not limited to the embodiments described.

[0055] Example 1: Preparation of Dually Modified Heteropolyacid Catalysts

[0056] (1) Preparation of heteropolyacids

[0057] 50.4 g of molybdenum trioxide, 44 g of nickel nitrate, and 5 g of potassium nitrate were dissolved in 300 g of deionized water, and then 6 g of 85% phosphoric acid was added and mixed thoroughly. The pH of the solution was adjusted to 3.0 with dilute nitric acid, and the mixture was stirred and refluxed at 90 °C for 4 h. The resulting solution was cooled, extracted with anhydrous diethyl ether, and evaporated to crystallize, yielding the heteropolyacid H₂KPMo₇Ni₅O. 40 .

[0058] (2) Preparation of dual-modified carrier

[0059] (a) Take 100g of silica gel pretreated by calcination at 300℃ for 8h. The average particle size of the silica gel is 15nm and the specific surface area is 300m². 2 / g, disperse it in 500g anhydrous ethanol and stir to obtain dispersion A at a stirring speed of 750rpm; disperse 5g wax (melting point of 105~110℃) in 100g anhydrous ethanol and stir to obtain dispersion B at a stirring speed of 750rpm.

[0060] (b) Add dispersion B to dispersion A and stir at 70°C for 6 hours at a stirring speed of 600 rpm. Dry the product at 75°C for 18 hours to obtain wax-modified silica gel with a wax content of 5% (based on the weight of unmodified silica gel).

[0061] (c) Disperse 10g of the wax-modified silica gel obtained above into 50g of anhydrous ethanol, and then add 0.2g of 3-aminopropyltriethoxysilane. Reflux at 80°C for 4h, filter, wash with anhydrous ethanol, and dry at 80°C for 6h to obtain silica gel with dual modification of wax and aminosilane.

[0062] (3) Preparation of dual-modified heteropolyacid catalysts

[0063] (a) 1g of heteropoly acid H2KPMo7Ni5O 40 Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0064] (b) 10g of the wax and aminosilane-modified silica obtained above were impregnated in a heteropoly acid solution for 16h at an impregnation temperature of 20°C, stirred, filtered, washed with anhydrous ethanol, and dried at 90°C for 6h to obtain a heteropoly acid catalyst with a heteropoly acid loading of 10wt% (based on the weight of the double-modified silica).

[0065] Example 2: Preparation of dual-modified heteropolyacid catalysts

[0066] (1) Preparation of heteropolyacids

[0067] Dissolve 53g Na₂WO₄·2H₂O, 4g cesium nitrate, and 7g cobalt nitrate in 200g deionized water, then add 2.5g of 85% phosphoric acid and mix thoroughly. Adjust the pH of the solution to 3.0 with dilute nitric acid, and reflux at 60°C for 8 hours with stirring. Cool the resulting solution, extract with anhydrous diethyl ether, and evaporate to crystallize, yielding the heteropolyacid bulk H₂CsPW₈Co₄O. 40 .

[0068] (2) The preparation method of the dual-modified carrier is the same as that in Example 1.

[0069] (3) Preparation of dual-modified heteropolyacid catalysts

[0070] (a) 1g of heteropolyacid H2CsPW8Co4O 40Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0071] (b) 10g of the wax and aminosilane-modified silica obtained above were impregnated in a heteropolyacid solution for 12h at an impregnation temperature of 30°C, stirred, filtered, washed with anhydrous ethanol, and dried at 75°C for 12h to obtain a heteropolyacid catalyst with a heteropolyacid loading of 10wt% (based on the weight of the double-modified silica).

[0072] Example 3

[0073] A method for preparing a dual-modified heteropolyacid catalyst, except that the amount of wax added is 10g and the wax content is 10%, the other preparation steps are the same as in Example 1.

[0074] Example 4

[0075] A method for preparing a dual-modified heteropolyacid catalyst, except that the amount of wax added is 20g and the wax content is 20%, the other preparation steps are the same as in Example 1.

[0076] Example 5

[0077] A method for preparing a dual-modified heteropolyacid catalyst, wherein the heteropolyacid H2KPMo7Ni5O is removed 40 The addition amount was 2g, the heteropolyacid loading was 20wt%, and 0.4g of 3-aminopropyltriethoxysilane was added. The other preparation steps were the same as in Example 3.

[0078] Example 6

[0079] A method for preparing a dual-modified heteropolyacid catalyst, wherein the heteropolyacid H2KPMo7Ni5O is removed 40 The addition amount was 3g, the heteropolyacid loading was 30wt%, and 0.4g of 3-aminopropyltriethoxysilane was added. The other preparation steps were the same as in Example 3.

[0080] Example 7 Preparation of dual-modified heteropolyacid catalysts

[0081] (1) Preparation of heteropolyacids

[0082] 9.2 g of vanadium pentoxide, 4.1 g of copper nitrate, 6 g of cesium nitrate, and 1.2 g of arsenic pentoxide were dissolved in 100 g of deionized water and mixed thoroughly. The pH of the solution was adjusted to 2.5 with dilute nitric acid, and the mixture was stirred and refluxed at 70 °C for 6 h. The resulting solution was cooled, extracted with anhydrous diethyl ether, and evaporated to crystallize, yielding the heteropolyacid HCs₂AsV. 10 Cu2O 40 .

[0083] (2) Preparation of dual-modified carrier

[0084] (a) Take 100g of silica gel pretreated by calcination at 500℃ for 4h. The average particle size of the silica gel is 30nm and the specific surface area is 200m². 2 / g, disperse it in 500g anhydrous ethanol and stir to obtain dispersion A at a stirring speed of 500rpm; disperse 5g wax (melting point of 90~95℃) in 100g anhydrous ethanol and stir to obtain dispersion B at a stirring speed of 500rpm.

[0085] (b) Add dispersion B to dispersion A and stir at 100°C for 3 hours at a stirring speed of 400 rpm. Dry the product at 75°C for 18 hours to obtain wax-modified silica gel with a wax content of 5% (based on the weight of unmodified silica gel).

[0086] (c) Disperse 10g of the wax-modified silica gel obtained above into 50g of anhydrous ethanol, and then add 0.2g of 3-aminopropyltrimethoxysilane. Reflux at 50°C for 8h, filter, wash with anhydrous ethanol, and dry at 80°C for 6h to obtain silica gel with dual modification of wax and aminosilane.

[0087] (3) Preparation of dual-modified heteropolyacid catalysts

[0088] (a) 1g of heteropolyacid HCs2AsV 10 Cu2O 40 Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0089] (b) 10g of the wax and aminosilane-modified silica obtained above were impregnated in a heteropoly acid solution for 8h at an impregnation temperature of 50°C, stirred, filtered, washed with anhydrous ethanol, and dried at 60°C for 15h to obtain a heteropoly acid catalyst with a heteropoly acid loading of 10wt% (based on the weight of the double-modified silica).

[0090] Example 8: Preparation of Dually Modified Heteropolyacid Catalysts

[0091] (1) The preparation method of heteropolyacids is the same as that in Example 7.

[0092] (2) Preparation of dual-modified carrier

[0093] (a) Take 100g of silica gel pretreated by calcination at 500℃ for 4h. The average particle size of the silica gel is 30nm and the specific surface area is 200m². 2 / g, disperse it in 500g anhydrous ethanol and stir to obtain dispersion A at a stirring speed of 500rpm; disperse 5g wax (melting point of 90~95℃) in 100g anhydrous ethanol and stir to obtain dispersion B at a stirring speed of 500rpm.

[0094] (b) Add dispersion B to dispersion A and stir at 95°C for 6 hours at a stirring speed of 300 rpm. Dry the product at 75°C for 18 hours to obtain wax-modified silica gel with a wax content of 5% (based on the weight of unmodified silica gel).

[0095] (c) Disperse 10g of the wax-modified silica gel obtained above into 50g of anhydrous ethanol, and then add 0.3g of vinyltris(2-methoxyethoxy)silane. Reflux at 65°C for 5h, filter, wash with anhydrous ethanol, and dry at 80°C for 6h to obtain wax and silane-modified silica gel.

[0096] (3) Preparation of dual-modified heteropolyacid catalysts

[0097] (a) 1g of heteropolyacid HCs2AsV 10 Cu2O 40 Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0098] (b) 10g of the wax and silane-modified silica obtained above was impregnated in a heteropolyacid solution for 12h at an impregnation temperature of 30°C, stirred, filtered, washed with anhydrous ethanol, and dried at 60°C for 15h to obtain a heteropolyacid catalyst with a heteropolyacid loading of 10wt% (based on the weight of the double-modified silica).

[0099] Example 9: Preparation of Dually Modified Heteropolyacid Catalysts

[0100] (1) The preparation method of heteropolyacids is the same as in Example 2.

[0101] (2) Preparation of dual-modified carrier

[0102] (a) Take 100g of silica gel pretreated by calcination at 300℃ for 8h. The average particle size of the silica gel is 15nm and the specific surface area is 300m². 2 / g, disperse it in 500g anhydrous ethanol and stir to obtain dispersion A at a stirring speed of 750rpm; disperse 5g wax (melting point of 105~110℃) in 100g anhydrous ethanol and stir to obtain dispersion B at a stirring speed of 750rpm.

[0103] (b) Add dispersion B to dispersion A and stir at 95°C for 6 hours at a stirring speed of 600 rpm. Dry the product at 75°C for 18 hours to obtain wax-modified silica gel with a wax content of 5% (based on the weight of unmodified silica gel).

[0104] (c) Disperse 10g of the wax-modified silica gel obtained above into 50g of anhydrous ethanol, and then add 0.1g of 3-aminopropyltriethoxysilane and 0.08g of mercaptopropyltrimethoxysilane. Reflux at 65°C for 5h, filter, wash with anhydrous ethanol, and dry at 80°C for 6h to obtain wax and silane-modified silica gel.

[0105] (3) Preparation of dual-modified heteropolyacid catalysts

[0106] (a) 1g of heteropolyacid H2CsPW8Co4O 40 Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0107] (b) 10g of the wax and silane-modified silica obtained above was impregnated in a heteropoly acid solution for 12h at an impregnation temperature of 30°C, stirred, filtered and washed, and dried at 60°C for 15h to obtain a heteropoly acid catalyst with a heteropoly acid loading of 10wt% (based on the weight of the double-modified silica).

[0108] Comparative Example 1

[0109] Preparation of heteropolyacid catalysts

[0110] (a) 1g of heteropoly acid H2KPMo7Ni5O 40 Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0111] (b) 10g of silica gel pretreated by calcination at 450℃ for 4h was used. The average particle size of the silica gel was 20nm and the specific surface area was 240m². 2 / g, is impregnated in a heteropoly acid solution for 12h at an impregnation temperature of 30℃, stirred, filtered, washed with anhydrous ethanol, and dried at 75℃ for 16h to obtain a heteropoly acid catalyst with a heteropoly acid loading of 10wt% (based on the weight of unmodified silica gel).

[0112] Comparative Example 2

[0113] Preparation of aminosilane-modified heteropolyacid catalysts

[0114] (a) 10g of silica gel pretreated by calcination at 450℃ for 4h was used. The average particle size of the silica gel was 20nm and the specific surface area was 240m². 2 / g, disperse it in 50g of anhydrous ethanol, then add 0.2g of 3-aminopropyltriethoxysilane, reflux at 65℃ for 5h, filter, wash with anhydrous ethanol, and dry at 80℃ for 6h to obtain aminosilane modified silica gel.

[0115] (b) Add 1g of heteropolyacid H2KPMo7Ni5O 40Dissolve in 20g of anhydrous ethanol and stir until homogeneous to obtain a 5% heteropolyacid solution.

[0116] (c) 10g of the aminosilane-modified silica obtained above was impregnated in a heteropoly acid solution for 12h at an impregnation temperature of 30°C, stirred, filtered and washed, and dried at 75°C for 12h to obtain an aminosilane-modified heteropoly acid catalyst with a heteropoly acid loading of 10wt% (based on the weight of the aminosilane-modified silica).

[0117] I. Performance Evaluation Experiments of Different Catalysts

[0118] The catalysts prepared in Examples 1-9 and Comparative Examples 1-2 were used in the synthesis of dicumyl peroxide for performance testing. The specific evaluation method was as follows: dimethylbenzyl alcohol (DMBA), acid catalyst, and cumyl peroxide (CHP) were added to the reactor in sequence for reaction. The molar ratio of DMBA to cumyl peroxide was 1.05:1, and the catalyst was added to cumyl peroxide at a weight ratio of 0.10%:1. The reaction temperature was 40°C, the vacuum degree was -0.04 MPa, and the reaction time was 5 h. The conversion rate of dicumyl peroxide (DCP), the selectivity of dicumyl peroxide, and the content of the byproduct AMS (α-methylstyrene) were detected. The test results for the examples and comparative examples are shown in Table 1.

[0119] Table 1 Performance evaluation results of each embodiment and comparative example

[0120]

[0121] Based on Examples 1, 2, and 7, it can be seen that by changing the type and number of central atoms, coordinating atoms, and counter cations, heteropolyacids with different acid sites and reactivity can be prepared. Their catalytic performance slightly affects the conversion and selectivity of the dicumyl peroxide (DCP) reaction and the formation of the byproduct AMS (α-methylstyrene). (HCs2AsV) 10 Cu2O 40 The performance evaluation results are slightly better than those of H2KPMo7Ni5O 40 and H2CsPW8Co4O 40 .

[0122] Based on Examples 1, 3, and 4, the hydrophobicity of the dual-modified heteropolyacid catalyst increases with increasing adsorbed wax content, which helps suppress the loss of the heteropolyacid active component supported on the dual-modified support. Based on Examples 3, 5, and 6, the concentration of the heteropolyacid active component on the catalyst increases with increasing heteropolyacid loading in the dual-modified support. Both of these aspects are beneficial for suppressing the generation of the byproduct AMS (α-methylstyrene) and improving the conversion rate and selectivity of the dicumyl peroxide (DCP) reaction. Based on Examples 7 and 8, the evaluation effect of using aminosilanes is slightly better than that of vinyl silanes. Based on Examples 2 and 9, the evaluation effect of using 3-aminopropyltriethoxysilane and mercaptopropyltrimethoxysilane is slightly better than that of 3-aminopropyltriethoxysilane.

[0123] Based on Examples 3 and Comparative Examples 1 and 2, compared to the unmodified heteropolyacid catalysts or single-modified heteropolyacid catalysts in the comparative examples, the dual-modified heteropolyacid catalyst of the present invention, with the synergistic effect of wax and silane modification, improves the hydrophobicity of the heteropolyacid catalyst, which is beneficial to reducing the loss of active components, resulting in good catalyst stability and high catalytic activity; it also facilitates catalyst dispersion in the reaction solution, leading to high catalytic efficiency. When this dual-modified heteropolyacid catalyst is applied to the synthesis of dicumyl peroxide, the reaction conditions are mild, reducing the generation of the byproduct AMS (α-methylstyrene) during the preparation of dicumyl peroxide, and improving the conversion rate and selectivity of the dicumyl peroxide synthesis reaction.

[0124] II. Performance Evaluation Experiments under Different Reaction Conditions

[0125] 1. Different feed ratios

[0126] The dual-modified heteropolyacid catalyst prepared in Example 2 was used for performance testing in the synthesis of dicumyl peroxide. The specific evaluation method was as follows: dimethylbenzyl alcohol (DMBA), the acid catalyst, and cumyl peroxide (CHP) were added to the reactor in sequence for reaction. The molar ratios of DMBA to CHP were 0.9:1, 1.05:1, and 1.2:1, respectively. The catalyst was added at a weight ratio of 0.10%:1. The reaction temperature was 40°C, the vacuum degree was -0.04 MPa, and the reaction time was 5 h. The conversion rate of dicumyl peroxide (DCP), the selectivity of dicumyl peroxide, and the content of the byproduct AMS (α-methylstyrene) were measured. The test results for the examples and comparative examples are shown in Table 2.

[0127] Table 2 Performance evaluation results for different feed ratios

[0128] 0.9:1 90.8 95.5 2.05 1.05:1 94.4 94.0 2.25 1.2:1 95.7 93.1 2.37

[0129] As can be seen from the experimental results in Table 2, with the increase of the feed ratio, the conversion rate of the DCP preparation reaction increases within the same reaction time. However, with the excess of DMBA, the content of AMS in the condensation solution increases and the selectivity decreases.

[0130] 2. Different catalyst dosages

[0131] The dual-modified heteropolyacid catalyst prepared in Example 2 was used in the synthesis of dicumyl peroxide for performance testing. The specific evaluation method was as follows: dimethylbenzyl alcohol (DMBA), the acid catalyst, and cumyl peroxide (CHP) were added to the reactor in sequence for reaction. The molar ratio of DMBA to CHP was 1.05:1. The catalyst and CHP were added at weight ratios of 0.05%:1, 0.10%:1, and 0.20%:1, respectively. The reaction temperature was 40℃, the vacuum degree was -0.04 MPa, and the reaction time was 5 h. The conversion rate of dicumyl peroxide (DCP), the selectivity of dicumyl peroxide, and the content of the byproduct AMS (α-methylstyrene) were measured. The test results for the examples and comparative examples are shown in Table 3.

[0132] Table 3 Performance evaluation results for different catalyst dosages

[0133] 0.05％:1 89.6 94.7 2.13 0.10％:1 94.4 94.0 2.25 0.20％:1 96.3 92.8 2.30

[0134] With the increase of catalyst dosage, the reaction rate for preparing DCP accelerates and the conversion rate increases. However, the increase of catalyst dosage easily leads to the decomposition side reaction of DMBA, the increase of AMS content in the condensation liquid, and the decrease of selectivity.

[0135] 3. Different vacuum levels

[0136] The dual-modified heteropolyacid catalyst prepared in Example 2 was used in the synthesis of dicumyl peroxide for performance testing. The specific evaluation method was as follows: dimethylbenzyl alcohol (DMBA), the acid catalyst, and cumyl peroxide (CHP) were added to the reactor in sequence for reaction. The molar ratio of DMBA to CHP was 1.05:1, and the catalyst and CHP were added at a weight ratio of 0.10%:1. The reaction temperature was 40℃, and the vacuum levels were -0.02 MPa, -0.04 MPa, and -0.06 MPa, respectively, for 5 hours. The conversion rate of dicumyl peroxide (DCP), the selectivity of dicumyl peroxide, and the content of the byproduct AMS (α-methylstyrene) were measured. The test results for the examples and comparative examples are shown in Table 4.

[0137] Table 4 Performance evaluation results for different vacuum levels

[0138] -0.02 87.6 96.1 1.94 -0.04 94.4 94.0 2.25 -0.06 96.0 93.0 2.35

[0139] As the vacuum level increases, it is beneficial for the removal of water generated in the reaction, which accelerates the reaction rate and increases the conversion rate of DCP preparation. However, the increase in vacuum level also easily leads to the dehydration and decomposition side reaction of DMBA. The experimental results show that the AMS content in the condensation solution increases and the selectivity decreases.

[0140] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The application of a dual-modified heteropolyacid catalyst in the synthesis of dicumyl peroxide, characterized in that, The dual-modified heteropolyacid catalyst is composed of an active component, heteropolyacid, and a support, wherein the support is a support dual-modified with a hydrophobic agent and a silane. The loading of the heteropoly acid is 2 to 40 wt% based on the weight of the dual-modified carrier; The hydrophobic agent includes alkane C. n H 2n+2 n = 15–40; the chemical formula of the silane is Y(CH2). n SiX3, n = 0 to 3, X is methoxy, ethoxy, or methoxyethoxy, Y is vinyl, amino, or mercapto; the silane is selected from one or more of the above-mentioned silanes; The preparation method of the heteropoly acid is as follows: 50.4g of molybdenum trioxide, 44g of nickel nitrate, and 5g of potassium nitrate are dissolved in 300g of deionized water, and then 6g of 85% phosphoric acid is added. The mixture is mixed evenly, and the pH of the solution is adjusted to 3.0 with dilute nitric acid. The solution is stirred and refluxed at 90°C for 4 hours. The resulting solution is cooled, extracted with anhydrous diethyl ether, and evaporated to crystallize, thereby obtaining the heteropoly acid.

2. The application of a dual-modified heteropolyacid catalyst in the synthesis of dicumyl peroxide, characterized in that, The dual-modified heteropolyacid catalyst is composed of an active component, heteropolyacid, and a support, wherein the support is a support dual-modified with a hydrophobic agent and a silane. The loading of the heteropoly acid is 2 to 40 wt% based on the weight of the dual-modified carrier; The hydrophobic agent includes alkane C. n H 2n+2 n = 15–40; the chemical formula of the silane is Y(CH2). n SiX3, n = 0 to 3, X is methoxy, ethoxy, or methoxyethoxy, Y is vinyl, amino, or mercapto; the silane is selected from one or more of the above-mentioned silanes; The preparation method of the heteropoly acid is as follows: 53g Na2WO4·2H2O, 4g cesium nitrate, and 7g cobalt nitrate are dissolved in 200g deionized water, and then 2.5g of 85% phosphoric acid is added and mixed evenly. The pH of the solution is adjusted to 3.0 with dilute nitric acid. The solution is stirred and refluxed at 60℃ for 8h. The resulting solution is cooled, extracted with anhydrous diethyl ether, and evaporated to crystallize, thereby obtaining the heteropoly acid.

3. The application of a dual-modified heteropolyacid catalyst in the synthesis of dicumyl peroxide, characterized in that, The dual-modified heteropolyacid catalyst is composed of an active component, heteropolyacid, and a support, wherein the support is a support dual-modified with a hydrophobic agent and a silane. The loading of the heteropoly acid is 2 to 40 wt% based on the weight of the dual-modified carrier; The hydrophobic agent includes alkane C. n H 2n+2 n = 15–40; the chemical formula of the silane is Y(CH2). n SiX3, n = 0 to 3, X is methoxy, ethoxy, or methoxyethoxy, Y is vinyl, amino, or mercapto; the silane is selected from one or more of the above-mentioned silanes; The preparation method of the heteropoly acid is as follows: 9.2g of vanadium pentoxide, 4.1g of copper nitrate, 6g of cesium nitrate and 1.2g of arsenic pentoxide are dissolved in 100g of deionized water and mixed evenly. The pH of the solution is adjusted to 2.5 with dilute nitric acid. The solution is stirred and refluxed at 70°C for 6 hours. The resulting solution is cooled, extracted with anhydrous diethyl ether, and evaporated to crystallize, thereby obtaining the heteropoly acid.

4. The application according to any one of claims 1-3, characterized in that, The substrate of the carrier is silicone; wherein the average pore size of the silicone carrier is 10–40 nm, and the specific surface area is 100–300 m². 2 / g.

5. The application according to any one of claims 1-3, characterized in that, The preparation method of the dual-modified heteropolyacid catalyst includes the following steps: (1) dissolving the active component heteropolyacid in anhydrous ethanol and stirring evenly to obtain a heteropolyacid solution; (2) immersing the hydrophobic agent and silane-modified support in the heteropolyacid solution at 10-60°C for 5-24 hours, stirring, filtering and washing, and drying at 40-120°C for 5-20 hours to obtain the dual-modified heteropolyacid catalyst; the molar ratio of silane to heteropolyacid is 1-3:

1.

6. The application according to claim 5, characterized in that, In step (2), the dual-modified carrier is prepared by the following method: (a) the carrier pretreated by calcination is dispersed in solvent 1 and stirred to obtain dispersion A at a stirring speed of 200-1000 rpm; the hydrophobic agent is dispersed in solvent 1 and stirred to obtain dispersion B at a stirring speed of 200-1000 rpm; the weight ratio of the hydrophobic agent to the carrier is 5-20:100; (b) dispersion B is added to dispersion A and stirred at 40-100°C for 2-8 hours at a stirring speed of 200-800 rpm; the product is dried at 50-90°C for 12-24 hours to obtain the hydrophobic agent modified carrier; (c) the hydrophobic agent modified carrier obtained above is dispersed in solvent 2, and silane is added and refluxed at 30-90°C for 2-10 hours, filtered, washed, and dried to obtain the dual-modified carrier.

7. The application according to claim 6, characterized in that, Solvent 1 is selected from one or more of methanol, ethanol or isopropanol; solvent 2 is selected from one or two of ethanol or methanol.

8. The application according to any one of claims 1-3, characterized in that, Using dimethylbenzyl alcohol and cumene hydroperoxide as raw materials, the molar ratio of dimethylbenzyl alcohol to cumene hydroperoxide is 0.9–1.2:1; the dual-modified heteropolyacid catalyst is added to cumene hydroperoxide at a weight ratio of 0.03%–0.30%:1; the reaction temperature is 30–50℃, the vacuum degree is -0.02–-0.08 MPa, and the reaction time is 2–8 h.

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